Surgical procedures are used to treat and cure a wide range of diseases, conditions, and injuries. Surgery often requires access to internal tissue through open or minimally invasive surgical procedures. The term “minimally invasive” refers to all types of minimally invasive surgical procedures, including endoscopic, laparoscopic, arthroscopic, natural orifice intraluminal, and natural orifice transluminal procedures.
Minimally invasive surgery can have numerous advantages compared to traditional open surgery, including reduced recovery time, pain, and surgery-related complications. In many minimally invasive procedures, the abdominal cavity is insufflated with carbon dioxide gas to provide adequate space to perform the procedure. The insufflated cavity is generally under pressure and is sometimes referred to as being in a state of pneumoperitoneum. Surgical access devices are often used to facilitate surgical manipulation of internal tissue while maintaining pneumoperitoneum. For example, during a surgical procedure, the abdominal wall can be pierced and a cannula or trocar can be inserted into the abdominal cavity. Surgeons can then perform a variety of procedures while minimizing patient trauma.
Various surgical instruments can be configured to manipulate tissue during a minimally invasive surgical procedure. An exemplary surgical instrument can include an actuator and an elongate shaft with an end effector that can be selectively coupled to the shaft and can articulate relative to the shaft. Such a device can include one or more modular features, such as an end effector that can be selectively attached to, and detached from, the shaft using a locking mechanism. The device can also include an inner shaft disposed within the elongate shaft, and the inner shaft can include a pointed tip for piercing the abdominal wall. Accordingly, the device can be inserted into a patient's body without an end effector attached by using the pointed tip of the inner shaft to form an incision in tissue. The end effector can then be selectively attached to the patient within, e.g., the abdominal cavity, to perform the procedure.
While the pointed tip of the instrument can be useful for piercing the abdominal wall, it can cause damage to surrounding tissue if the instrument is inserted too far into a patient's body. Even if the instrument is not over-inserted distally, moving the pointed tip around within the body can cause undesirable damage to nearby tissue. Furthermore, it is also possible that a user can easily withdraw the surgical device from the patient's body inadvertently, both when an end effector is attached thereto and, especially, when no end effector is attached because of the low profile of the elongate shaft alone.
In addition, surgical devices configured to selectively couple to end effectors within the body can sometimes employ a clevis-like attachment mechanism that includes opposed arms that are radially deflectable to allow insertion into a socket formed on an end effector. The opposed arms of the attachment mechanism can, in some embodiments, be quite small and thin. There is a risk that these arms can become permanently bent or otherwise deformed if, for example, an end effector is not correctly aligned during coupling (e.g., if only one of the arms enters the socket on the end effector while the other arm remains outside the socket, the arms can be bent away from one another). It is also possible that tissue or other nearby structures can catch one of the arms during insertion and/or withdrawal of the device.
Accordingly, there is a need for improved devices and methods that assist users in preventing over-insertion and/or unintentional withdrawal of a device being passed through tissue. There is also a need for devices and methods that protect against damage to an attachment mechanism used to couple to an end effector.